fix: repair cross-package bugs so all tests and tsc pass

[stooit]

Summary

Fixes all failing tests and type errors across the monorepo. bun test reports 13 pass / 0 fail and tsc --noEmit is clean. No test files modified; no dependencies added.

Bugs fixed

#	File	Bug	Fix
1	apps/web/src/lib/api.ts	Imported/re-exported renamed hook useThrottle (no longer exported by @e2e/utils)	Import & re-export useDebounce (canonical name) as useSearchDebounce
2	packages/utils/src/format/date.ts	Zero-padded day (01/03/2024) and risk of day/month confusion	Use Intl.DateTimeFormat("en-AU", { dateStyle: "short" }) → d/MM/yyyy (no leading-zero day, local-time safe)
3	bunfig.toml	Root test runs lacked a happy-dom preload → document is not defined in UI tests	Add preload of the UI happy-dom setup to [test]
4	packages/ui/src/components/Button/Button.tsx	ariaLabel prop destructured but never applied	Apply aria-label to the <button>
5	packages/ui/src/components/DataTable/DataTable.tsx	Stale-closure sort toggle caught by controlled re-render test	Use functional updater setSortDir(prev => ...)
6	tsconfig.json	bun:test unresolved (TS2307)	Add "types": ["bun-types"]

Verification

• bun test → 13 pass / 0 fail
• npx tsc --noEmit → clean
• No files under test/ or *.test.* were changed.

Assumptions

• The canonical hook export in @e2e/utils is useDebounce (confirmed in packages/utils/src/index.ts).
• en-AU short date style is the intended format the date test targets; chosen over manual UTC extraction to avoid an off-by-one for non-UTC-timezone callers.
• Reviewed via the review subagent; the only finding (UTC off-by-one) was addressed by the locale-based formatter.